(19)

(11)

EP 2 686 520 A2

(12)

(88) Date of publication A3: 12.12.2013 (43) Date of publication: 22.01.2014 Bulletin 2014/04 (21) Application number: 12759983.5 (22) Date of filing: 05.03.2012

(51) International Patent Classification (IPC):  E21B 49/00(2006.01) (86) International application number: PCT/US2012/027686 (87) International publication number: WO 2012/128921 (27.09.2012 Gazette 2012/39)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR (30) Priority: 18.03.2011 US 201113051573 (71) Applicant: Weatherford/Lamb, Inc. Houston, TX 77056 (US)	(72) Inventor: BRUMBOIU, Aurel Calgary, Alberta T2Z 3J2 (CA) (74) Representative: Shanks, Andrew  Marks & Clerk LLP Aurora 120 Bothwell Street Glasgow G2 7JS Glasgow G2 7JS (GB)